Molecular Clouds in the Milky Way: the Columbia-Chile CO Survey and Detailed Studies with the KOSMA 3 m Telescope

Abstract

The first extensive survey of the molecular clouds in the Milky Way galaxy in both the northern and southern hemisphere on the scale of several thousand square degrees was completed less than one year ago by DAME et al. [1]. Two 1.2m radio telescopes, one located in New York City, the other in Chile, were used to sample about 7700 deg² with the angular resolution degraded to 0.5° in order to cover large areas quickly. Other surveys used significantly higher angular resolution but have been limited to selected nearby molecular clouds and a thin strip covering the inner galactic plane. The most extensive of these surveys are:

• 1. the ¹²CO survey with the Columbia and Chile telescopes operating at their full angular resolution of 1/8° (see, e.g., COHEN et al. [2], BRONFMAN et al. [3]),

• 2. the ¹³CO survey with the 7 m dish of Bell Laboratories (see, e.g., BALLY et al. [4], [5]), and

• 3. the ¹²CO survey with the 14 m FCRAO telescope (see, e.g., SANDERS et al. [6], CLEMENS et al. [7]).